Gas-spring with an adjustable device to brake and/or fix the gas spring stroke

ABSTRACT

A gas-spring arrangement includes a gas-spring which has a substantially tubular, external casing (2) and a rod (3) which is guided for axial movement in the casing, between two terminal positions and is dampened by means of gas constrictions. The gas-spring includes attachment links at each end for attachment of the gas-spring between mutually movable devices or structures, such as a pivoted hood on a sunbed. The gas-spring arrangement includes a friction device (6) which is operative to brake the relative axial movement between the gas-spring casing (2) and the gas-spring rod (3), and also to fix the casing (2) and the rod (3) in selective relative positions, i.e., positions between the terminal positions, and when combined with a hooded sunbed, can maintain the hood in a desired raised position.

The present invention pertains to a gas-spring arrangement in which theso-called gas spring includes a substantially tubular outer casing and arod which is guided for axial movement in the tubular casing, betweentwo terminal positions and is dampened with the aid of gasconstrictions, and further includes means for attachment of the gasspring.

BACKGROUND OF THE INVENTION

Gas springs are used, inter alia, to dampen the relative movementbetween two movable parts. One example of such use is found in so-calledsun-bed constructions in which the upper part, or canopy, of the bedstructure can be moved between a position in which the canopy liesessentially contiguous with the bottom part of said structure, i.e. thebed surface, and an upwardly swung position, in which the canopy ispositioned at an angle to the bed surface.

SUMMARY OF THE INVENTION

The present invention relates to a gas-spring arrangement which enablesthe gas-spring to be secured readily and detachably in selectedlocations between said terminal positions, therewith obviating the needto provide separate, complicated stop and fixating devices, among otherthings.

The invention thus relates to a gas-spring arrangement in which theso-called gas-spring includes a substantially tubular outer casing, arod which is guided for axial movement in the casing between twoterminal positions and is dampened with the aid of gas constrictions,and which further includes means for attaching the gas-spring betweendevices or structures capable of movement therebetween. The gas-springarrangement is particularly characterized in that it includes a frictiondevice which is operative to brake or retard the relative axial movementof the casing and the rod and also to fixate the casing and rod inselective relative positions, essentially positions located betweenterminal positions of extension and retraction of the gas-spring.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference toexemplifying embodiments thereof and also with reference to theaccompanying drawings, of which

FIG. 1 illustrates schematically a first embodiment of an inventivearrangement, and shows the friction device in axial section;

FIG. 2 is an axial sectional view of a friction device substantiallyaccording to FIG. 1;

FIG. 3 is a sectional view taken on the line 3--3 in FIG. 2;

FIG. 4 is an end view of the friction device housing looking in thedirection of 4--4 in FIG. 2;

FIG. 5 is and end view of the sleeve of the friction device seen in FIG.2;

FIG. 6 is a schematic axial sectional view taken on line 6--6 accordingto of FIG. 8, through a second embodiment of the inventive arrangement;

FIG. 7 shows the arrangement illustrated in FIG. 6 from beneath;

FIG. 8 shows the arrangement illustrated in FIG. 6 from above;

FIG. 9 illustrates schematically an inventive gas-spring arrangementfitted to a sun-bed construction provided with an electric hoistarrangement for movement of the canopy part of the sun-bed, said sun-bedbeing seen in its longitudinal direction;

FIG. 10 shows the sun-bed of FIG. 9 from the left in said Figure;

FIG. 11 shows the sun-bed of FIG. 9 from the right in said Figure;

FIG. 12 illustrates schematically a sun-bed panel construction as shownin FIG. 11, but without a backpiece;

FIG. 13 is a schematic sectional view taken on 13--13 of FIG. 12; and

FIG. 14 is a schematic sectional view taken on 14--14 of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, the reference 1 identifies a gas-spring which is shown inchain lines and which includes a substantially tubular, outer casing 2,a rod 3 which is guided for axial movement into and out of the hollowcasing 2, between two terminal positions and is dampened herewith bymeans of gas constrictions (not shown), said gas-spring furtherincluding attachment parts 4, 5 for attachment of the gas-spring betweenrelatively movable devices or structures, not shown.

FIGS. 1 and 2-5 illustrate an embodiment of a friction device 6 which iseffective in braking or retarding the relative axial movement of thecasing 2 and the rod 3, and the device, in appropriate circumstances,can be used to fixate the casing and the rod in selective relativepositions, substantially positions located between said terminalpositions. The illustrated friction device comprises a housing 7 whichis intended to be fitted externally onto the gas-spring casing 2,preferably at one end 2', and held firmly in position at said one end,and includes clamping members8 arranged around the rod 3 and connectedto said housing, these clamping members preferably being intended to bebrought into clamping engagement with the rod 3, with the aid ofscrew-type devices. In the case of the illustrated embodiment, the screwdevices comprise a nut arrangement 9 which coacts with the outer face 7'of the housing through the intermediary of the screwthreads 9'. Theillustrated nut arrangement is such that when said nut arrangement isscrewed toward the housing and unscrewed therefrom, the clamping memberswill generate continuous, variable clamping forces, for example throughthe intermediary of conical faces 10. In the case of the illustratedembodiment, the clamping members 8 define a substantially cylindricalconfiguration around the rod 3, and are slightly conically shapedexternally, wherewith the clamping members will be displaced radially toa given extent by means of axially movable ring-part 11 on the nutarrangement 9, these ring-part acting externally on the clampingmembers. The illustrated clamping members 8 comprise four mutuallyidentical parts separated by axially extending slots.

The housing 7 has an internal flange 12 which coacts with acorresponding groove 13 in the casing, such as to enable the housing tobe snapped firmly into engagement with the casing.

Illustrated in FIGS. 6-8 is an embodiment in which a housing 14 isintendedto be fitted externally to the casing 2 and firmly securedthereto. A radial slot 15 extends axially along the housing 16, to formhousing partsor clamping parts 16 extending substantially around the rod3, wherewith a screw 17 or some like device is provided for increasingor decreasing the width of the slot 15 such as to vary continuously theclamping forces exerted by the clamping parts 16. This embodiment isalso provided with aninternal flange, referenced 18, corresponding tothe aforedescribed flange 12 of the FIG. 1 embodiment.

FIGS. 9-14 illustrate schematically a sun-bed 19. The upper part orcanopy 20 of the sun-bed is raised and lowered with the aid of anelectric hoist arrangement which is complemented with the inventivegas-spring arrangements, such as the gas-spring illustrated in FIG. 1.The gas-springarrangements are primarily intended to replace the hoistarrangement as canopy positioning means during breakdowns in operation.The sun-bed of the illustrated embodiment includes a box-like base 21, alower part 22 which rests on the base 21, an upright panel construction23 which is mounted on the base 21, the lower part 22 and the canopy 20,said canopy being rotatably journalled on the panel 23 for pivotalmovement towards and away from the lower bed part.

As will be seen from FIGS. 12-14, the major part of the hoistarrangement is located in the panel. The reference 24 identifies arotational shaft which is rotatably journalled in the panel structureand extends through and along said panel structure and which isconnected with the canopy 20, preferably externally of the side walls 25of said panel, for swinging of the canopy, e.g., with the aid of endparts 26 extending transversely of the shaft 24. The shaft 24 is rotatedby means of an electric motor 27, via a winding shaft 28 rotated bymeans of said motor, a winding element 29, such as a belt or strap 29,arranged between the shaft 28 and an auxiliary arm 30 projectingtransversely to the shaft 24 and intended to be wound onto and unwoundfrom said shaft, so as to shorten or lengthen, respectively, the freebelt lengths between the shaft and an outer part 31, such as an end part31, of the auxiliary arm 30, such as to rotate theshaft 24. Thus, when acanopy raise-pulse is delivered to the motor, preferably by a controlmeans 32 on the panel, the hoist arrangement will function to wind thebelt or strap 29 onto the shaft 28, so as to swing the auxiliary arm 30and rotate the shaft 24, and therewith raise the canopy 19. When themotor receives a canopy lowering pulse, through the aforesaid controlmeans 32, the belt or strap is unwound from the shaft and the canopylowers gravitationally, under its own weight. Although not shown,position limit switches are provided for defining the highest and lowestlevel to which the canopy can move.

In order to enable the canopy to be manoeuvered and positioned withoutthe aid of the electric hoist arrangement, two gas-spring arrangementsare mounted between the canopy and the lower bed part, one at each endwall ofthe sun-bed and preferably relatively close to said panelstructure. The gas-spring is referenced 1 and the friction device isreferenced 6. When the electric hoist arrangement is in active use, thegas-spring arrangements are adjusted to a non-friction mode. Adjustmentof the gas-spring arrangements to "manual" will enable the canopy of thesun-bed to be lowered manually to its lowermost position and then raisedto a position substantially midway between the lowest and the highestcanopy positions, the friction device of respective gas-springarrangements beingadjusted so that the canopy is braked and the weightof said canopy counter-balanced, such that said canopy will remain inits manually adjusted position unless acted upon by forces other thanthose generated by its own weight.

The control panel structure 23 preferably also incorporates four fans33, with individual controls 34, for blowing ventilating air onto thesun-bed and also houses a timer, control means for automatic cooling ofthe sun-bed, and the requisite cables.

The method of operation of the inventive arrangement will be understoodin all essentials from the aforegoing. Through the intermediary of thecontinuous, variable clamping forces generated by the friction device,it is possible to achieve a desired braking force with respect to mutualmovement between the casing 2 and the rod 3. The braking force can beincreased to an extent such as to lock the casing and the rod relativeto one another.

It will be understood from the aforegoing that the invention affordsimportant advantages in the form, inter alia, of increased flexibilitywhen using gas-springs, and also novel possibilities of use.

The invention has been described in the aforegoing with reference to anexemplifying embodiment thereof. It will be understood, however, thatmodifications and minor changes can be made, without departing from thescope of the inventive concept.

For instance, embodiments are conceivable in which the friction deviceis attached to the rod 3 instead of the casing 2 and has clampingmembers or the like which act on said casing. The clamping members maybe located externally, as with the clamping members 8, 16, orinternally, wherewith radially displaceable parts are arranged to actagainst the inner wall or corresponding surface of the casing, such asto achieve braking of relative movement between the casing and the rod,and when appropriate to lock or fixate said casing rod against relativemovement.

When the friction device is attached to the casing, the clamping membersacting against the rod may be located inside the casing 2 instead ofoutside the casing as, for instance, in accordance with FIG. 1.

It will be understood, that when using the embodiment illustrated inFIGS. 9-14, the construction of both the gas-spring arrangement and thehoist arrangement can be varied.

Consequently, the invention is not restricted to the aforedescribedembodiments but modifications can be made within the scope of thefollowing claims.

What is claimed and desired to be secured by Letters Patent is:
 1. Agas-spring arrangement comprising a substantially tubular, outer casing,a rod which is guided for axial movement in the casing between twoterminal positions and dampened through the action of gas constrictions,and further including attachment means on said rod and on said casingfor attaching the gas-spring between mutually movable devices, saidgas-spring arrangement further including an adjustable friction clampdevice (6) which is secured on said gas spring and engages both of saidrod and said casing and is operative to brake the relative axialmovement between the casing (2) and the rod (3) and also can be adjustedto fix the casing (2) and the rod (3) relative to one another in any ofa multiplicity of desired selected positions, at and between saidterminal positions.
 2. An arrangement according to claim 1, whereinmeans secure the friction device (6) to the casing (2) and said frictionclamp device includes clamping means (8, 16) which engage and clampagainst the rod (3), to fix said rod relative to said casing.
 3. Anarrangement according to claim 1, wherein means secure said frictiondevice (6) to the rod (3) and said friction clamp device includesclamping means which engage against the casing (2) to fix said casingrelative to said rod.
 4. A gas-spring arrangement comprising asubstantially tubular, outer casing, a rod which is guided for axialmovement in the casing between two terminal positions and dampenedthrough the action of gas constrictions, and further includingattachment means on said rod and on said casing for attaching thegas-spring between mutually movable devices, said gas-spring arrangementfurther including an adjustable friction device (6) which is secured onsaid gas spring and engages both of said rod and said casing and isoperative to brake the relative axial movement between the casing (2)and the rod (3) and also can be adjusted to fix the casing (2) and therod (3) relative to one another in desired selected positions, betweensaid terminal positions; said friction device (6) comprising a housing(7) with a cylindrical part fitted externally over the casing (2) of thegas spring, and said casing and said cylindrical part includecooperative means securing said friction device firmly on said casing;and said friction device further comprising clamping means (8; 16)connected to the housing (7) and disposed around said rod (3), and screwmeans connected to said clamping means to move said clamping means intoselectively adjustable clamping engagement with said rod, by screwingsaid screw means.
 5. An arrangement according to claim 4, wherein anintegral part of said housing comprises said clamping means which has aradially and axially extending slot (15), and said screw means (17) isin said integral part of said housing adjacent said clamping means slotand is operative to vary the width of said slot (15) to generatecontinuous, selectively variable clamping forces by said clamping meanson said rod.
 6. An arrangement according to claim 4, wherein said screwmeans includes a nut and threads on said housing whereby said nut can bescrewed and unscrewed on said housing (7) to thereby generatecontinuous, selectively variable clamping forces on said rod by saidclamping means.
 7. An arrangement as defined in claim 6, wherein saidclamping means are an annular group of spaced-apart fingers with conicalouter surfaces converging from the housing toward said rod and said nuthas a ring part encircling said conical fingers and movable back andforth along said fingers as said nut is screwed back and forthrespectively on the threads on said housing.
 8. A sun-bed constructionwith two long sides and two ends comprising: an elongate bed base part;an elongate canopy (20) and a means pivotally securing one long side ofsaid canopy to a long side of said bed base part; said canopy havingsun-bed radiation sources fitted thereto; and said canopy beingjournalled by said pivotal means for rotation about the axis of alongitudinal rotational shaft (24) located at said long side of said bedbase part, pivotal movement of said canopy being provided by a poweredhoist means; and a gas-spring arrangement connected between said canopyand said bed base part including means enabling holding of said canopyin a desired pivoted position relative to said bed base part; saidgas-spring arrangement including: at least one gas spring with asubstantially tubular, outer casing, a rod which is guided for axialmovement in said casing between two terminal positions and dampenedthrough the action of gas constrictions in the gas spring, and furtherincluding attachment means on said casing and on said rod which connectthe gas-spring between mutually movable parts on said canopy and saidbed base part, and wherein said gas-spring arrangement further includesan adjustable friction clamp device (6) secured on said at least one gasspring and which engages both the rod and the casing of said gas springand is operative to brake the relative axial movement between the casing(2) and the rod (3) of said gas spring and can also be adjusted to fixthe casing (2) and the rod (3) relative to one another in any of amultiplicity of desired selected positions, at and between said terminalpositions.
 9. A sun-bed construction according to claim 8, wherein thesun-bed construction is provided with two said gas-springs, one at eachend of the sun-bed construction, each gas-spring being arranged tofunction between the canopy (20) and the bed base part (22) of thesun-bed.
 10. A sun-bed construction according to claim 8, wherein thecanopy (20) is carried by a longitudinally extending panel structure(23) which is mounted adjacent and between one long side of the canopyand one long side of the bed base part of said sun-bed.
 11. A sun-bedconstruction according to claim 8, wherein a longitudinally extending,rotatably journalled shaft (24) is connected to said canopy to effectpivoting movement of said canopy, and an electric motor (27) with awinding shaft (28) driven by said motor, and a winding element (29),arranged between the winding shaft (28) and an auxiliary arm (30) on andprojecting transversally to the journalled shaft (24), and which isintended to rotate said journalled shaft when the winding shaft isrotated by said motor.